Bipolar battery assembly

ABSTRACT

The invention relates to an article comprising: a) one or more stacks of battery plates comprising one or more bipolar plates; b) located between each plate is a separator and a liquid electrolyte; further comprising one of more of the features: 1) c) the one or more stacks of battery plates having a plurality of channels passing transversely though the portion of the plates having the cathode and/or the anode deposited thereon; and d) i) one or more seals about the periphery of the channels which prevent the leakage of the liquid elelctrolyte into the channels, and/or posts located in one or more of the channels having on each end an overlapping portion that covers the channel and sealing surface on the outside of the monopolar plates adjacent to the holes for the transverse channels and applies pressure on the sealing surface of the monopolar plates wherein the pressure is sufficient to withstand pressures created during assembly and operation of electrochemical cells created by the stacks of battery plates; 2) c) a membrane comprising a thermoplastic polymer is disposed about the entire periphery of the edges of the stack of plates; 3 wherein the separator is in the form of a sheet having adhered to its periphery a frame; andm4) c) an integrated valve and integrated channel communicating with the valve.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of co-pending applicationU.S. Ser. No. 14/345,321, filed Mar. 17, 2014 which a national phaseapplication of Patent Cooperation Treaty application PCT/US2012/033744,filed Apr. 16, 2012 which claims priority from U.S. ProvisionalApplication 61/550,657 filed Oct. 24, 2011.

FIELD

The present invention relates generally to a bipolar battery assembly,to methods for the preparation of such assemblies and to methods ofusing such assemblies.

BACKGROUND

Bipolar batteries are known in the art, see Tatematsu US 2009/0042099,incorporated herein by reference in its entirety. Bipolar batteriesprovide advantages over other battery designs such as scalability,relatively high energy density, high power density and designflexibility. Bipolar batteries comprise a number of bipolar plates andtwo monopolar end plates. A bipolar plate comprises a substrate which isin the form of a two sided sheet having a cathodic material, oftenreferred to a Positive Active Material (PAM), on one surface and on theopposite side is an anodic material, often referred to a Negative ActiveMaterial (NAM). A conductive sheet may be disposed between the substrateand the anodic material or cathodic material. The bipolar plates arearranged in a stack such that the anodic material of one plate faces thecathodic material of the next plate. In most assemblies there is abattery separator located between the adjacent plates which allow anelectrolyte to flow from cathodic material to the anodic material.Disposed in the space between the plates is an electrolyte, which is amaterial that allows electrons and ions to flow between the anodic andcathodic material. The adjacent surfaces of the bipolar plates with theseparator and the electrolyte disposed between the plates form anelectrochemical cell wherein electrons and ions are exchanged betweenthe anodic material and the cathodic material. The structure of thebattery is arranged such that each cell formed by the bipolar plates issealed to prevent flow of electrolyte out of the cell The structure usedto seal each electro-chemical cell is in contact with the portion of theplates not having anodic or cathodic material on the substrate. Inaddition the battery separator can extend beyond the portion of thesubstrate having the anodic and cathodic material disposed thereon toaid in sealing the cells. Each cell has a current conductor connected tothe cell to transmit electrons from the cell to one or more terminalsfrom which the electrons are transmitted to a load, in essence anothersystem that utilizes the electrons in the form of electricity. In someembodiments the current conductor in a cell is the conductive sheetwhich is in contact with additional current conductors which transmitthe electrons to the terminals of the battery. At each end of the stackis a monopolar plate having either anodic material or cathodic materialdisposed on one face. The material on the face of the monopolar plate isselected to form a cell with the opposing face of the bipolar plate atthat end of the stack. In particular if the bipolar plate facing themonopolar plate has cathodic material on the face of the plate then themonopolar plate has anodic material on its face and vice versa. Inconventional designs the stack of battery plates are disposed in a casewhich is sealed about the stack of plates and has one or more pairs ofpositive and negative terminals located on the outside of the battery,each pair is connected to a current conductor further connected to oneof more cells as described herein.

Despite the advantages of bipolar battery assemblies, the disadvantagesof bipolar battery assemblies have prevented them from beingcommercialized. Bipolar batteries during operation generate significantinternal pressures due to expansion and contraction of anodic andcathodic material, gas evolution during the electrochemical process andheat generated. Because bipolar batteries are scalable higher pressuresin the cells can be generated. In addition, the heat evolved canexacerbate the pressures generated and can result in runaway reactionswhich can generate heat levels that damage the materials of constructionof the batteries and render the batteries non-functional. The pressurescan cause the seals about the electrochemical cell to rupture and renderthe cells and battery nonfunctional. Commonly owned patent applicationtitled BIPOLAR BATTERY ASSEMBLY, Shaffer II, et al. US 2010/0183920,incorporated herein by reference in its entirety, discloses solutions tothese problems through improved edge sealing assemblies and bipolarplate designs.

There are still needs to be addressed before bipolar batteries can becommercialized and the full potential of this technology can beachieved. In particular, bipolar battery designs that handle the heatand pressures generated in operation in an improved manner are needed.Present and future users of batteries often have limited packaging spaceavailable for batteries and batteries that can be adapted to availablepackaging space are needed. Most systems using batteries also desirelighter weight batteries and bipolar batteries which exhibit lowerweights, are desired. Bipolar battery designs that reduce parts andcomplexity, such as special parts used for sealing of the electricalcells and separate cases are desired. Batteries that minimize volume andincrease power output are desired, that is batteries with enhanced powerdensity are desired. Methods for battery assembly that are simpler andutilize known manufacturing techniques and achieve the abovementionedgoals are needed. Batteries that can be scaled to fit the user needs areneeded.

SUMMARY

The present disclosure meets one or more of the above needs and is anarticle comprising: a) two or more stacks of battery plates comprisingone or more bipolar plates comprising a substrate having an anode on onesurface and a cathode on the opposite surface wherein the substratesconduct current from one surface to the other surface; b) a firstmonopolar plate having a cathode deposited on one surface, a currentcollector in contact with the cathode, disposed at one end of the two ormore stacks of battery plates; c) a second monopolar plate having ananode deposited on one surface, a current collector in contact with theanode, disposed at one end of the two or more stacks of battery plates;wherein the monopolar plates are located at opposite ends of the two ormore stacks of battery plates and the plates are arranged such that thesurfaces of the plates having a cathode deposited on the surface facethe surface of another plate having an anode deposited on the surface;d) located between each battery plate is a separator and a liquidelectrolyte which forms an electrochemical cell; e) disposed between twoof the two or more stacks of battery plates is a dual polar batteryplate comprising a first conductive substrate having two opposingsurfaces with anode material deposited on one surface and a firstcurrent conductor in contact with a portion of the opposite surface; asecond conductive substrate having two opposing surfaces with cathodematerial deposited on one surface and a second current conductor incontact with a portion of the opposite surface; and a non-conductivesubstrate that is disposed between the first and second conductivesubstrates; the dual polar battery plate is arranged between two of thetwo or more battery stacks such that the surfaces of the plate having ananode deposited on the surface faces the surface of another plate in afirst battery stack having a cathode deposited on the surface and thesurface of the plate having a cathode material deposited on the surfacefaces the surface of the plate in a second battery stack having an anodedeposited on the surface; and f) one or more conductive conduits whichconnects the current conductors directly or indirectly to batteryterminals; In some embodiments a membrane is formed by welding a sheetof thermoplastic material about the edge of the plates, preferably byvibration or heat welding. In some embodiments the membrane is formed bymolding it about the plates, preferably by injection molding. Thebattery stacks may be connected in series by connecting the two currentconductors for each dual polar plate through a conductive conduit. Thebattery stacks may be connected in parallel by connecting the positivecurrent conductors, those connected to a cathode through a conductivesubstrate, through one or more conductive conduits to the positiveterminal, directly or indirectly and by connecting the negative currentconductors, those connected to an anode through a conductive substrate,through one or more conductive conduits to the negative terminal,directly or indirectly. A conductive connector may be placed in contactwith one or both of the monopolar plates. The conductive connector maybe placed between the end plate or membrane about the battery assemblyand the conductive substrate of the monopolar plate. These are theterminal conductive connectors of a battery assembly and may protrudethrough the case or membrane about the battery assembly and may functionas battery terminals or connect to the battery terminals. The terminalpositive conductive connector is in contact with the monopolar end platewith a cathode. The terminal negative conductive connector is in contactwith the monopolar end plate with an anode.

The articles disclosed are useful as batteries for the storage ofelectricity and to generate electricity for use in a variety ofenvironments. The articles disclosed provide high power input with atlower required volumes and weights, thus providing a high power density.The articles are designed to handle the pressures and heat generatedduring operation without undue damage to the outside surface of thearticle and so that the liquid electrolyte is contained in the article.The articles disclosed can be assembled using conventional materials andprocesses. The articles disclosed are capable of achieving the recitedadvantages without the requirement of complex sealing structures. Thearticles disclosed can be adapted to different shaped spaces toaccommodate a user's packaging space. The design of the articlesdisclosed allows scaling the size to deliver a variety of energy needsto the user. Assembly of the articles disclosed is more efficient thanassembly of articles known in the art. The articles disclosed canwithstand pressures of up to about 10 psi, preferably up to about 50 psiand most preferably up to about 100 psi on the end plates of thestructure without damaging the end plates. The electrochemical cells aresealed in a manner such that the final assembly can be oriented in anymanner which is suitable for the final use and the packaging spaceavailable. The devices do not require orientation with a specified topportion and bottom portion requiring orientation with the top orientedup and the bottom oriented down that is in the direction of gravity.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of an assembly disclosed.

FIG. 2 is side view of an assembly disclosed having an end plate over abolt in a transverse channel.

FIG. 3 is a side view of an assembly with a membrane disposed about thestack of bipolar plates.

FIG. 4 shows an assembly disclosed with a manifold and a check valve.

FIG. 5 illustrates a separator sheet disclosed.

FIG. 6 illustrates another embodiment of an assembly disclosed whereinposts are injection molded into the transverse channels.

FIGS. 7 and 8 illustrates stacks of battery plates and separator plates.

FIG. 9 shows another embodiment of an assembly disclosed.

FIG. 10 shows a cutaway view of the assembly of FIG. 9 through a pair oftransverse channels along plane A-A.

FIG. 11 shows a partial cut away view of the end of a stack showing thevent holes along line B-B.

FIG. 12 shows a cutaway view of the assembly of FIG. 9 though the ventholes to the electrochemical cells along plane C-C.

FIG. 13 shows another embodiment of an assembly disclosed with a valvein the end plate of the assembly.

FIG. 14 shows a cutaway view of the assembly of FIG. 13 though anintegrated channel in communication with the vent holes to theelectrochemical cells along plane E-E.

FIG. 15 shows a cutaway view of the assembly of FIG. 13 though anintegrated channel in communication with the vent holes to theelectrochemical cells along plane D-D.

FIG. 16 illustrates a separator having an absorbent glass mat as shownin FIGS. 5 and 7 containing a vent notch in an insert (vent hole).

FIG. 17 shows a side view of a cut out from a separator having an insertwith a notch in the insert forming a vent communicating between the holeand the absorbent glass mat.

FIG. 18 shows a portion of two bipolar plates with a portion of aseparator disposed between them with the inserts aligned to form avent/fill channel.

FIG. 19 shows the construction of a dual polar plate that does not allowtransport of electrons or ions between the anode and cathode andprovides for electrical communication outside of the battery.

FIG. 20 shows two stacks of batteries separated by a dual polar platewhich wherein the two battery stacks are connected in parallel

FIG. 21 shows three stacks of battery plates separated by two dual polarplates wherein the stacks are connected in series.

DETAILED DESCRIPTION

The explanations and illustrations presented herein are intended toacquaint others skilled in the art with the invention, its principles,and its practical application. Those skilled in the art may adapt andapply the invention in its numerous forms, as may be best suited to therequirements of a particular use. Accordingly, the specific embodimentsof the present invention as set forth are not intended as beingexhaustive or limiting of the invention. The scope of the inventionshould be determined with reference to the appended claims, along withthe full scope of equivalents to which such claims are entitled. Thedisclosures of all articles and references, including patentapplications and publications, are incorporated by reference for allpurposes.

The disclosure relates to an article useful as a battery comprising twoor more stacks of a plurality of bipolar plates, two monopolar plateslocated on each end of the two or more stacks of bipolar plates, havinga liquid electrolyte disposed between the bipolar plates; whereindisposed between two of the two or more stacks of battery plates aredual polar battery plates each comprising a first conductive substratehaving two opposing surfaces with anode material deposited on onesurface and a first current conductor on the opposite surface; a secondconductive substrate having two opposing surfaces with cathode materialdeposited on one surface and a second current conductor on oppositesurface and; and a non-conductive substrate that is disposed between thefirst and second conductive substrates; the dual polar battery plate isarranged between two or more battery stacks such that the surfaces ofthe plate having an anode deposited on the surface faces the surface ofanother plate in a first battery stack having a cathode deposited on thesurface and the surface of the plate having a cathode material depositedon the surface faces the surface of the plate in a second battery stackhaving an anode deposited on the surface. Where there are more than twostacks of battery plates a dual polar battery plate may be disposedbetween each pair of stacks of battery plates. For example if there arefour stacks of battery plates there are three dual polar battery plateseach with a stack of battery plates adjacent to the anodes and cathodesof the dual polar battery plates. The battery plates have monopolarplates adjacent to the end cathode or anode of the battery stacks toform the end electrochemical cells. Each of the monopolar plates containa current conductor in contact with a portion of the conductivesubstrate of the monopolar plate which is disposed away from the anodeor cathode. The monopolar current conductors may be disposed between theconductive substrate and the end plate or case about the assembly. Thesecurrent conductors may protrude through the case or membrane. If thesecurrent conductors do not protrude through the case or membrane acurrent conduit may be present to connect them to the positive ornegative terminals.

The articles and processes of the invention may further comprise one ormore of the features listed below in any combination, includingpreferences and alternative embodiments disclosed in this application:wherein the bipolar plates comprise polymeric substrates having aplurality of openings passing through the substrates in communicationwith both surfaces of the substrates wherein one or more of the openingsare straight and have smooth surfaces and are filled with a conductivematerial that undergoes a phase transformation at a temperature that isbelow the thermal degradation temperature of the polymeric substrates; amembrane comprising a polymer is disposed about the entire periphery ofthe stack of plates of two or more battery stacks so as to form a sealabout the edges of the plates which prevents the liquid electrolyte fromflowing outside of the stack of plates; the membrane has a leading edgeand a trailing edge and the leading edge and the trailing edge of themembrane are melt bonded to one another such that the membrane forms aseal about the periphery of the one or more stacks of plates such thatelectrolytes do not pass from inside of the stack to outside themembrane; the one or more separators comprise sheets having anintegrated frame adhered to the periphery of the sheets wherein theintegrated frames are adapted to be placed adjacent to the periphery ofthe substrates of the battery plates; the substrates for the batteryplates have raised surfaces about their periphery adapted to be disposedadjacent to the integrated frames of the separators; the integratedframes about the periphery of the separators; an integrated channelwhich comprises holes or slots in the separators and battery plates thatare aligned to form one or more sealed channels which are transverse tothe plane of the battery plates and separators and the channels comprisevent holes which communicate with the electrochemical cells,; whereinthe holes in the separators and the battery plates contain inserts,bosses or sleeves located therein wherein the inserts are adapted tomate to form the integrated channel in the two or more stacks of batteryplates; the channels may be formed by inserts that are molded to thebattery plates and separators; the channels may be formed by sleeves orbushings placed between the battery plates and separators; the batteryplates have indentations adapted for the sleeves and/or bushings to fitinto; the sleeves and/or bushings have ends that insert into the batteryplates and/or separators; the sleeves or bushings are bonded to thebattery plates and/or separators thereby forming seals at the junction;the channel comprises a series of matched inserts or bosses; theinserts, bosses or sleeves in contact with the separator may containvent holes that communicate between the integrated channel and theelectrochemical cells, the vent holes may be formed by notches in theinserts, bossed or sleeves, the article further comprises one or more avalves adapted to release pressure in the sealed stacks of bipolarplates when the pressure reaches a predetermined pressure level which isbelow a pressure at which damage to the article could occur; a valve isconnected to the integrated channel; the one or more stacks of batteryplates having a plurality of channels passing transversely though theportion of the plates having the cathode and/or the anode depositedthereon; one or more seals about the periphery of the channels whichprevent the leakage of the liquid electrolyte into the channels, andposts located in one or more of the channels having on each end anoverlapping portion that covers the channel and sealing surface on theoutside of the monopolar plates adjacent to the holes for the transversechannels and applies pressure on the sealing surface of the monopolarplates wherein the pressure is sufficient to withstand pressures createdduring assembly and operation of electrochemical cells created by thestacks of battery plates; posts located in one or more channels havingon each end a portion that covers the channel and a sealing surface onthe outside of the monopolar plates adjacent to the holes for thetransverse channels and applies pressure on the sealing surface of themonopolar plates wherein the pressure is sufficient to withstandpressures created during assembly and operation of electrochemical cellscreated by the stacks of battery plates wherein the post is fabricatedfrom a material that is capable of withstanding exposure to theelectrolyte and prevents the electrolyte from entering the channels; thearticle comprises seal about the periphery of the transverse channelspassing transversely though the portion of the plates having the cathodeand/or the anode deposited thereon; the seal is formed by inserts aremolded to the battery plates and separators; the seal is formed bysleeves or bushings placed between the battery plates and separators;the battery plates have indentations adapted for the sleeves and/orbushings to fit into; the sleeves and/or bushings have ends that insertinto the battery plates; the sleeves or bushings are bonded to thebattery plates thereby forming seals at the junction; the seal comprisesa series of matched inserts or bosses; wherein the article does notcomprise a seal about the periphery of the transverse channels and thepost comprises a material that maintains its structural integrity whenexposed to the electrolyte, is nonconductive and seals the transversechannels so as to prevent electrolyte from entering the channels; theposts comprise a ceramic material or a polymeric material of ABS,polypropylene, polyester, thermoplastic polyurethanes, polyolefins,compounded thermoplastic resins or polycarbonates; the posts arepre-molded and comprise nonconductive polymers which are disposed in thechannels by interference fit; the posts comprise ABS; the cathode of themonopole plate and the cathode of the internal plate with a cathode andanode current collector are connected to independent positive terminals;the anode of the monopole plate and the anode of the internal plate witha cathode and anode current conductor are connected to independentnegative terminals; the internal sets of cells are independentlyelectrochemically formed; the positive conductive conductors areconnected and the negative conductive conductors are connected inparallel; or the battery stacks are connected in series; the batterystacks are connected in series by connecting the two current conductorsfor each dual polar plate through a conductive conduit; the batterystacks may be connected in parallel by connecting the positive currentconductors, those connected to a cathode through a conductive substrate,through one or more conductive conduits to the positive terminal,directly or indirectly and by connecting the negative currentconductors, those connected to an anode through a conductive substrate,through one or more conductive conduits to the negative terminal,directly or indirectly; a conductive connector may be placed in contactwith one or both of the monopolar plates; a conductive connector isplaced between the end plate or membrane about the battery assembly andthe conductive substrate of the monopolar plate; the terminal conductiveconnectors of a battery assembly protrude through the case or membraneabout the battery assembly and function as battery terminals or connectto the battery terminals; the terminal positive conductive connector isin contact with the monopolar end plate with a cathode; and the terminalnegative conductive connector is in contact with the monopolar end platewith an anode.

Articles disclosed comprise one or more bipolar electrode plates,preferably a plurality of bipolar plates. Plurality as used herein meansthat there are more than one of the plates. A bipolar plate comprises asubstrate in the form of a sheet having two opposing faces. Located onthe opposing faces are a cathode and an anode. In some embodiments thebipolar plates are arranged in the articles in stacks wherein thecathode of one bipolar plate faces the anode of another bipolar plate ora monopolar plate having an anode and the anode of each bipolar platefaces the cathode of a bipolar or monopolar plate. In the article aspace is formed between the adjacent anodes and cathodes wherein thespace contains electrolyte which functions with the anode and cathodepair to form an electrochemical cell. The construction of the articlesresults in closed cells which are sealed from the environment to preventleakage and short circuiting of the cells. The number of the platespresent can be chosen to provide the desired voltage of the battery. Thebipolar battery design provides flexibility in the voltage that can beproduced. The bipolar plates can have any desired cross sectional shapeand the cross sectional shape can be designed to fit the packaging spaceavailable in the use environment. Cross-sectional shape refers to theshape of the plates from the perspective of the faces of the sheets.Flexible cross-sectional shapes and sizes allow preparation of thearticles disclosed to accommodate the voltage and size needs of thesystem in which the batteries are utilized. Monopolar plates aredisposed on the ends of the stacks of plates to form end cells of thestack of plates. The monopolar plates may be prepared from the samesubstrates and anodes and cathodes used in the bipolar plates. The sideof the monopolar plate opposing the anode or cathode can be the baresubstrate when another case is used or it can contain a covering usefulto protect the stack. The monopolar plates may have one or moreterminals passing through the plate from the end cell to the outside orpassing through the side of the case or membrane about the assemblyessentially parallel to the plane of the monopolar plates. The terminalmatches the polarity of the anode or cathode of the monopolar plate. Theterminal functions to transmit the electrons generated in theelectrochemical cells to the system that utilizes the generatedelectrons in the form of electricity. The cathode of the monopole plateand the cathodes of one or more of the internal plates with a cathodecurrent collector may be connected to independent positive terminals.The anode of the monopole plate and the anodes of one or more of theinternal plates with an anode current collector may be connected toindependent negative terminals. The cathode current collectors may beconnected and the anode current collectors may be connected in parallel.The individual terminals may be covered in a membrane leaving only asingle connected positive and a single connected negative terminalexposed.

The substrate of the battery plates functions to provide structuralsupport for the cathode and/or the anode; as a cell partition so as toprevent the flow of electrolyte between adjacent cells; cooperating withother battery components to form an electrolyte-tight seal about thebipolar plate edges which may be on the outside surface of the battery;and may transmit electrons from one surface to the other. The substratecan be formed from a variety of materials depending on the function orthe battery chemistry. The substrate may be formed from materials thatare sufficiently structurally robust to provide the backbone of adesired bipolar electrode plate, withstanding temperatures that exceedthe melting points of any conductive materials used in the batteryconstruction, and having high chemical stability during contact with anelectrolyte (e.g., sulfuric acid solution) so that the substrate doesnot degrade upon contact with an electrolyte. The substrate may beformed from suitable materials and/or is configured in a manner thatpermits the transmission of electricity from one surface of thesubstrate to an opposite substrate surface. The substrate plate may beformed from an electrically conductive material, e.g., a metallicmaterial, or can be formed from an electrically non-conductive material.Exemplary non-conductive material include polymers; such as thermosetpolymers, elastomeric polymers or thermoplastic polymers or anycombination thereof. The non-conductive substrate may have electricallyconductive features constructed therein or thereon. Examples ofpolymeric materials that may be employed include polyamide, polyester,polystyrene, polyethylene (including polyethylene terephthalate, highdensity polyethylene and low density polyethylene), polycarbonates (PC),polypropylene, polyvinyl chloride, bio-based plastics/biopolymers (e.g.,polylactic acid), silicone, acrylonitrile butadiene styrene (ABS), orany combination thereof, such as PC/ABS (blends of polycarbonates andacrylonitrile butadiene styrenes). Composite substrates may be utilized,the composite may contain reinforcing materials, such as fibers orfillers commonly known in the art, two different polymeric materialssuch as a thermoset core and a thermoplastic shell or thermoplastic edgeabout the periphery of the thermoset polymer, or conductive materialdisposed in a non-conductive polymer. The substrate may comprise or haveat the edge of the plates a thermoplastic material that is bondable,preferably melt bondable. The substrate may have a raised edge about theperiphery so as to facilitate stacking of the bipolar plates andformation of electrochemical cells. The raised edge as used in thiscontext means a raised edge on at least one of the two opposing surfacesof the plates. The raised edge may comprise a thermoplastic edge portionformed about another substrate material. The raised edge may function asseparator plates as described herein. The substrate or periphery of thesubstrate a non-conductive material, and may be a thermoplasticmaterial. The frame about or integrated onto the substrate may becomprised of non-conductive material, such as a thermoplastic material.The use of non-conductive material enhances sealing the outside of thebattery stack.

The substrate comprises a generally non-electrically conductivesubstrate (e.g., a dielectric substrate) that includes one or moreopenings formed therein. The openings may be machined (e.g., milled),formed during fabrication of the substrate (e.g., by a molding orshaping operation), or otherwise fabricated. The openings may havestraight and/or smooth internal walls or surfaces. The size andfrequency of the openings formed in the substrate may affect theresistivity of the battery. The openings may be formed having a diameterof at least about 0.2 mm. The openings may be formed having a diameterof about 5 mm or less. The openings may be formed having a diameter fromabout 1.4 mm to about 1.8 mm. The openings may be formed having adensity of at least about 0.02 openings per cm². The openings may beformed having a density of less than about 4 openings per cm². Theopenings may be formed having a density from about 2.0 openings per cm²to about 2.8 openings per cm². The openings may be filled with anelectrically conductive material, e.g., a metallic-containing material.The electrically conductive material may be a material that undergoes aphase transformation at a temperature that is below the thermaldegradation temperature of the substrate so that at an operatingtemperature of the battery assembly that is below the phasetransformation temperature, the dielectric substrate has an electricallyconductive path via the material admixture between the first surface andthe second surface of the substrate. Further, at a temperature that isabove the phase transformation temperature, the electrically conductivematerial admixture undergoes a phase transformation that disableselectrical conductivity via the electrically conductive path. Forinstance, the electrically conductive material may be or include asolder material, e.g., one comprising at least one or a mixture of anytwo or more of lead, tin, nickel, zinc, lithium, antimony, copper,bismuth, indium or silver. The electrically conductive material may besubstantially free of any lead (i.e., it contains at most trace amountsof lead) or it may include lead in a functionally operative amount. Thematerial may include a mixture of lead and tin. For example, it mayinclude a major portion tin and a minor portion of lead (e.g., about 55to about 65 parts by weight tin and about 35 to about 45 parts by weightlead). The material may exhibit a melting temperature that is belowabout 240° C., below about 230° C., below about 220° C., below 210° C.or even below about 200° C. (e.g., in the range of about 180 to about190° C.). The material may include a eutectic mixture. A feature ofusing solder as the electrically conductive material for filling theopenings is that the solder has a defined melting temperature that canbe tailored, depending on the type of solder used, to melt at atemperature that may be unsafe for continued battery operation. Once thesolder melts, the substrate opening containing the melted solder is nolonger electrically conductive and an open circuit results within theelectrode plate. An open circuit may operate to dramatically increasethe resistance within the bipolar battery thereby stopping furtherelectrical flow and shutting down unsafe reactions within the battery.Accordingly, the type of electrically conductive material selected fillthe openings can vary depending on whether it is desired to include suchan internal shut down mechanism within the battery, and if so at whattemperature it is desired to effect such an internal shutdown. Thesubstrate will be configured so that in the event of operatingconditions that exceed a predetermined condition, the substrate willfunction to disable operation of the battery by disrupting electricalconductivity through the substrate. For example, the electricallyconductive material filling holes in a dielectric substrate will undergoa phase transformation (e.g., it will melt) so that electricalconductivity across the substrate is disrupted. The extent of thedisruption may be to partially or even entirely render the function ofconducting electricity through the substrate disabled.

Disposed on one surface of the bipolar plates and on some of themonopolar plates is one or more cathodes. The cathode can be in anymaterial that is capable of functioning as a cathode in a battery andcan be in any form commonly used in batteries. The cathode is alsoreferred to as positive active material. The positive active materialmay comprise a composite oxide, a sulfate compound or a phosphatecompound of lithium, lead, carbon or a transition metal generally usedin a lithium ion, nickel metal hydride or lead acid secondary battery.Examples of the composite oxides include Li/Co based composite oxidesuch as LiCoO₂, Li/Ni based composite oxide such as LiNiO₂, Li/Mn basedcomposite oxide such as spinel LiMn₂O4, and Li/Fe based compositematerials such as LiFeO₂. Exemplary phosphate and sulfur compounds oftransition metal and lithium include LiFePO₄, V₂O₅, MnO₂, TiS₂, MoS₂,MoO₃, PbO₂, AgO, NiOOH and the like. The cathode material can be in anyform which allows the cathode material to function as a cathode in anelectrochemical cell. Exemplary forms include formed parts, in pasteform, pre-fabricated sheet or film. For lead acid, batteries thepreferred cathode material is lead dioxide (PbO₂). Disposed on theopposite surface of the bipolar plates and the other monopolar plate arethe anodes. The anodes are also referred to as negative active material.Any anode and anode material may be utilized in the assembliesdisclosed. The anode material may include any material used in secondarybatteries, including lead acid, nickel metal hydrides and lithium ionbatteries. Exemplary materials useful in constructing anodes includelead, composite oxides of carbon or lithium and transition metal, (suchas a composite oxide of titanium oxide or titanium and lithium) and thelike. The anode material for a lead acid battery may be sponge lead. Thecathode material can be in any form which allows the cathode material tofunction as a cathode in an electrochemical cell. Exemplary formsinclude formed parts, in paste form, pre-fabricated sheet or films.Paste compositions can contain a number of beneficial additivesincluding floc or glass fibers for reinforcement, various ligano-organiccompounds for paste stability and conductive additives such as carbon,particularly for negative active materials. For lead acid batteries thepreferred form of the anode material is sponge lead. The anode andcathode are chosen to work together to function as an electrochemicalcell once a circuit is formed which includes the cells.

The assemblies further comprise separators. The separators are locatedbetween the anode and the cathode in electrochemical cells, morespecifically separators are located between the bipolar plates orbetween a bipolar plate and a monopolar plate. The separators preferablyhave an area that is greater than the area of the adjacent cathode andanode. The separator may completely separate the cathode portion of thecell from the anode portion of the cell. The edges of the separator maycontact peripheral edges of the bipolar and monopolar plates which donot have an anode or cathode disposed thereupon so as to completelyseparate the anode portion of the cell from the cathode portion of thecell. A battery separator functions to partition electrochemical cells;to prevent short circuiting of the cells due to dendrite formation;functions to allow liquid electrolyte, ions, electrons or anycombination of these elements to pass through it. Any known batteryseparator which performs one or more of the recited functions may beutilized in the assemblies of the invention. The separator may beprepared from a non-conductive material, such as porous polymer films,glass mats, porous rubbers, ionically conductive gels or naturalmaterials, such as wood, and the like. The separator may contain poresor tortuous paths through the separator which allows electrolyte, ions,electrons or a combination thereof to pass through the separator. Amongexemplary materials useful as separators are absorbent glass mats, andporous ultra-high molecular weight polyolefin membranes and the like.

The separators may have integrated frames. The frames function to matchwith the edges of adjacent battery plates and to form a seal between theelectrochemical cells and the outside of the battery. The frame can beattached to the separator about the periphery of the sheet forming theseparator using any means that bonds the separator to the frame andwhich can withstand exposure to the electrolyte solution, for example byadhesive bonding, melt bonding or molding the frame about the peripheryof the separator. The frame can be molded in place by any known moldingtechnic, for example thermoforming, injection molding, roto molding,blow molding, compression molding and the like. The frame may be formedabout the separator sheet by injection molding. The frame may contain araised edge adapted to match raised edges disposed about the peripheryof the substrates for the battery plates. Raised edges in one or both ofthe battery plate substrates and the frames of the separators can bematched to form a common edge for the battery stack and to enhance theseal between the electrochemical cells and the outside of the battery.The separators may have inserts integrated into the separator whereinthe inserts function to define the transverse channels through thestack. The inserts may be formed by any known means and are preferablymolded in place, preferably by injection molding. Where a separator hasboth inserts and a frame both parts can be molded in one step, forinstance by injection molding. The inserts may contain vent holes toallow communication of selected fluids from the electrochemical cells tothe transverse channels. Each of the electrochemical cells may beindependently electrochemically formed.

The articles may comprise conductive materials in a shape whichfacilitates dispersing the electrons flowing in the electrochemical cellso as to ensure electrical connection of the active materials to thesubstrate and may function as current collectors. Exemplary conductivematerials include metal sheets, foils, screens or a plurality of metalwires arranged in a common plane. The battery plates may contain currentconduits which transmit the electrons between the stacks of batteryplates and the negative and positive battery terminals. The dual polarbattery plates contain a negative current conductor disposed on theopposite side of the conductive substrate from the surface containingthe anode. The negative current conductor is disposed in contact withthe conductive substrate and the nonconductive substrate and protrudesfrom the battery stack. The protruding portion is contacted with acurrent conduit that may transport current between the negative currentconductor and the negative terminal or the positive current conductor ofthe same plate. The dual polar battery plates contain a positive currentconductor disposed on the opposite side of the conductive substrate fromthe surface containing the cathode. The positive current conductor isdisposed in contact with the conductive substrate and the nonconductivesubstrate and protrudes from the battery stack. The protruding portionis contacted with a current conduit that transports current between thepositive current conductor and the positive terminal or the negativecurrent conductor of the same plate. At least one each of the negativeand positive current conductors may protrude out of the battery assemblythrough a cover about the battery assembly, such as a membrane. The endnegative and positive current conductors may protrude out of the batteryassembly and may connect to or function as the negative and positiveterminals respectively. Positive and negative current conductors may beconnected to dual polar battery plates, monopolar battery plates or bothtypes of plates may have the current conductors connected thereto. Thepositive and negative current conductors which protrude through themembrane or battery case may be in contact with dual polar batteryplates or monopolar battery plates. When the battery stacks areconnected in parallel the negative current conductors are connected by anegative current conduit to the negative terminal or the negativecurrent conductor that also functions as a negative terminal and thepositive current conductors are connected by a positive current conduitto the positive terminal or the positive current conductor that alsofunctions as a positive terminal. When the battery stacks are connectedin series a conductive conduit connects the positive current conductorof each dual polar battery plate to the negative current conductor ofthe same dual polar battery plate. The current conduit comprises anyconductive material that transmits current and may be in anyconfiguration of shape that facilitates transmission of current. Themetal sheets, screens, foils or wires can be prepared from anyconductive metal. Exemplary conductive metals are silver, tin, copper,lead or mixtures of two or more thereof. The selection of the metal isinfluenced by the anode and cathode materials. In a lead-acid batteries,lead sheets or foils may be used. The metal foils, screens, sheets orwires useful as current collectors may be located between the anode orcathode and the substrate. The metal sheets, screens, foils or wires maybe affixed to the substrate. Any method of affixing the metal sheet,screen, foil or wire to the substrate that holds the metal sheet,screen, foil or wire to the substrate in the environment of the cellsmay be utilized, such as welding or adhesive bonding. The metal sheets,screens, foils or wires may be adhesively bonded to the substrate.Exemplary adhesives useful for this bonding include epoxies, rubbercements, phenolic resins, nitrile rubber compounds or cyanoacrylateglues. The metal sheets, screens, foils or wires may be located betweenthe entire surface of the anode or cathode and the substrate. The metalsheets, screens, foils or wires may cover the entire surface of thesubstrates. The current collector may be a metal sheet or foil. Wherethe anode or cathode is in paste form, the paste may be applied to themetal foil or sheet or applied over the metal screen or wires bonded tothe substrate. The metal sheet, screen, foil or wires may contact one ormore current conductors to transmit electrons to the current conductors.The metal sheets, screens, wires or foils are chosen to be thick enoughto disperse electrons flowing through the cells and where appropriate tocollect electrons and transmit them to current conductors in the cell.The metal sheets, screens, wires or foils may function as the currentconductors. The metal sheets, screens, wires or foils may have athickness of about 0.75 mm or less, about 0.2 mm or less or about 0.1 mmor less. The metal sheets, screens, foils or wires may have a thicknessof about 0.025 mm or greater, about 0.050 mm or greater or about 0.075mm or greater.

The dual polar battery plates comprise a first conductive substratehaving two opposing surfaces with anode material deposited on onesurface and a first current conductor in contact with a portion of theopposite surface; a second conductive substrate having two opposingsurfaces with cathode material deposited on one surface and a secondcurrent conductor in contact with the opposite surface; and anon-conductive substrate that is disposed between the first and secondconductive substrates; the dual polar battery plate is arranged betweentwo of the two or more battery stacks such that the surfaces of theplate having an anode deposited on the surface faces the surface ofanother plate in a first battery stack having a cathode deposited on thesurface and the surface of the plate having a cathode material depositedon the surface faces the surface of the plate in a second battery stackhaving an anode deposited on the surface. The conductive anodes,cathodes, conductive substrates and current conductors of the dual polarbatteries are as described herein. Disposed between the first and secondconductive substrates is a nonconductive substrate. The nonconductivesubstrate may be prepared from any nonconductive material as disclosedherein. The nonconductive substrate should have a sufficient area andcross-sectional thickness to insulate between the first substrate andthe first current conductor and the second conductive substrate andsecond current conductor. The non-conductive substrate may have an areathat is greater that the area of the cathode or anode on the conductivesubstrates. The non-conductive substrate may have a thickness of about0.1 mm or greater or about 0.5 mm greater. The non-conductive substratemay have a thickness of about 1.5 mm or less or about 1.0 mm or less.The nonconductive substrate is arranged to prevent the first and secondcurrent collectors from coming into contact with one another. The firstand second current collectors have opposite polarities. Thenon-conductive substrates may be prepared from any of the non-conductivematerials useful for the substrates described hereinbefore. Thenonconductive substrates may have frames about their periphery whereinthe frames are a disclosed with respect to the conductive substrates andseparators. The frames may be integrated with the non-conductivesubstrates.

The battery stacks may be connected in series by connecting the twocurrent conductors for each dual polar plate through a conductiveconduit. The battery stacks may be connected in parallel by connectingthe positive current conductors, those connected to a cathode through aconductive substrate, through one or more conductive conduits to thepositive terminal, directly or indirectly and by connecting the negativecurrent conductors, those connected to an anode through a conductivesubstrate, through one or more conductive conduits to the negativeterminal, directly or indirectly. A conductive connector may be placedin contact with one or both of the monopolar plates. The conductiveconnector may be placed between the end plate or membrane about thebattery assembly and the conductive substrate of the monopolar plate.These are the terminal conductive connectors of a battery assembly andmay protrude through the case or membrane about the battery assembly andmay function as battery terminals or connect to the battery terminals.The terminal positive conductive connector is in contact with themonopolar end plate with a cathode. The terminal negative conductiveconnector is in contact with the monopolar end plate with an anode.

The stack of components in the assembly may contain transverse channelspassing through the components and the area formed for theelectrochemical cells which cells also contain a liquid electrolyte. Thestack includes bipolar plates, monopolar plates, separators, anodes,cathodes, optionally current collectors (metal sheets, screens, wires orfoils), dual polar battery plates and any other components of the stackwhich may be utilized. The transverse channels function to house theposts and some of the channels may be left unfilled so as to function astransverse cooling channels or vent/fill channels. The channels passthrough the anode, cathode and the cells containing the electrolyte. Thechannels may be sealed to prevent electrolytes and gasses evolved duringoperation from entering the channels. Any method of sealing whichachieves this objective may be utilized. The size and shape of thechannels can be any size or shape which allows them to house the postsand the posts to support the end plate and edges of the substrates toprevent leakage of electrolytes and gasses evolved during operation andto prevent the compressive forces arising during operation from damagingcomponents and the seal for the individual electrochemical cells or tofunction as cooling or vent channels. The shape of the channels may beround, elliptical or polygonal, such as square, rectangular, hexagonaland the like. The size of the channels housing posts is chosen toaccommodate the posts used. The channels comprise a series of holes inthe components arranged so a post can be placed in the channel formed orso that a fluid can be transmitted through the channel for cooling orfor venting and filling. The number of channels is chosen to support theend plate and edges of the substrates to prevent leakage of electrolytesand gasses evolved during operation and to prevent the compressiveforces arising during operation from damaging components and the sealfor the individual electrochemical cells. A plurality of channels may bepresent so as to spread out the compressive forces generated duringoperation. The number and design of channels is sufficient to minimizeedge-stress forces that exceed the fatigue strength of the seals. Thelocations of the channels are chosen so as to spread out the compressiveforces generated during operation. The channels may be spread out evenlythrough the stack to better handle the stresses. The channels may have across-sectional size of about 2 mm or greater, about 4 mm or greater orabout 6 mm or greater. The upper limit on the cross-sectional size ofthe channels is practicality, if the size is too large the efficiency ofthe assemblies is reduced. The channels may have a cross-sectional sizeof about 12 mm or less or about 10 mm or less.

Located in at least some of the channels are posts which perform one ormore of the following functions: hold the stack of components togetherin a fashion such that damage to components or breaking of the sealbetween the edges of the components of the stack is prevented, ensureuniform compression across the separator material, and ensure uniformthickness of the separator material. The posts may have on each end anoverlapping portion which engages the outside surface of the monopolarend plates. This overlapping portion functions to apply pressure on theoutside surface of the monopolar end plates in a manner so as to preventdamage to components or breaking of the seal between the edges of thecomponents of the stack, and prevent bulging or other displacements ofthe stack during battery operation. The overlapping portion is incontact with a sealing surface, the portion of the end plate in contactwith the overlapping portion. The stack may have a separate structuralor protective end-piece over the monopolar endplate and the overlappingportion will be in contact in with the outside surface of the structuralor protective end-piece. The overlapping portion can be any structurethat in conjunction with the post prevents damage to components orbreaking of the seal between the edges of the components of the stack.Exemplary overlapping portions include bolt heads, nuts, molded heads,brads, cotter pins, shaft collars and the like. The posts are of alength to pass through the entire stack and such length varies based onthe desired capacity of the battery. The posts may exhibit across-section shape and size so as to fill the channel. The posts mayhave a cross-sectional size greater than the cross-sectional size of thechannels so that the posts form an interference fit in the channels. Thenumber of posts is chosen to support the end plate and edges of thesubstrates to prevent leakage of electrolytes and gasses evolved duringoperation and to prevent the compressive forces arising during operationfrom damaging components and the seal for the individual electrochemicalcells, and to minimize edge-stress forces that exceed the fatiguestrength of the seals. The plurality of posts may be present so as tospread out the compressive forces generated during operation. There maybe fewer posts than channels where one or more of the channels areutilized as cooling channels or vent/fill channels. The posts maycomprise any material that performs the necessary functions. If the postis utilized to seal the channels then the material used is selected towithstand the operating conditions of the cells, will not corrode whenexposed to the electrolyte and can withstand the temperatures andpressures generated during operation of the cells. Where the postsperform the sealing function the posts may comprise a polymeric orceramic material that can with stand the conditions recited. In thisembodiment the material must be non-conductive to prevent shorting outof the cells. The posts may comprise a polymeric material such as athermoset polymer or a thermoplastic material. The posts may comprise athermoplastic material. Exemplary thermoplastic materials include ABS(acrylonitrile-butadiene-styrene copolymers), polypropylene, polyester,thermoplastic polyurethanes, polyolefins, compounded thermoplasticresins, polycarbonates and the like. ABS is most preferred. Where thechannels are separately sealed the posts can comprise any material thathas the structural integrity to perform the desired functions. Thepolymeric materials recited above, ceramics and metals may be utilized.Suitable metals may be steel, brass aluminum, copper and the like. Theposts can comprise molded posts, threaded posts or posts with one ormore end attachments. The posts may be bonded to parts of the stacks,for example the substrates, inserts or bosses in the channels, and thelike. The bonds can be formed from adhesives or fusion of the polymericmaterials, such as thermoplastic materials. Where the parts are threadedthe structural parts of the stack are threaded to receive the threadedposts. Posts can have a head on one end and a nut, hole for a brad orcotter pin on the other or may have a nut, hole for a brad or cotter pinon both ends. This is generally the case for non-molded posts. The postsmay be constructed in such a way as to be a one way ratcheting devicethat allows shortening, but not lengthening. Such a post would be put inplace, then as the stack is compressed, the post is shortened so that itmaintains the pressure on the stack. The post in this embodiment mayhave ridges that facilitate the ratcheting so as to allow the posts tofunction as one part of a zip tie like structure. Matching nuts and/orwashers may be used with posts so as to compress the plates they areadjacent to when in place. The nuts and/or washers go one way over theposts and ridges may be present to prevent the nuts and/or washers frommoving the other direction along the posts. In use the holes in theposts will have the appropriate brads, cotter pins and the like toperform the recited function. If the post is molded is can be moldedseparately or in place. If molded in place, in situ, a seal needs to bepresent in the channel to hold the molten plastic in place. Anonconductive post which is threaded may be used and can provide thenecessary seal. Alternatively a pre-molded nonconductive polymeric postmay be designed to form an interference fit in the channel in a mannerso as seal the channels. The posts may be formed in place by molding,such as by injection molding.

When assembled the stack of components, including the bipolar andmonopolar plates, form sealed electrochemical cells. Located in thesealed cells is a liquid electrolyte. The electrolyte can be any liquidelectrolyte that facilitates an electrochemical reaction with the anodeand cathode utilized. The electrolyte allows electrons and ions to flowbetween the anode and cathode. The electrolytes can be water based ororganic based. The organic based electrolytes useful herein comprises anelectrolyte salt dissolved in an organic solvent. In lithium ionsecondary batteries, it is required that lithium be contained in theelectrolyte salt. For the lithium-containing electrolyte salt, forinstance, use may be made of LiPF₆, LiClO₄, LiBF₄, LiAsF₆, LiSO₃CF₃ andLiN(CF₃SO₂)₂ . These electrolyte salts may be used alone or incombination of two or more. The organic solvent should be compatiblewith the separator, cathode and anode and the electrolyte salt. It ispreferable to use an organic solvent that does not decompose even whenhigh voltage is applied thereto. For instance, it is preferable to usecarbonates such as ethylene carbonate (EC), propylene carbonate (PC),butylene carbonate, dimethyl carbonate (DMC), diethyl carbonate andethyl methyl carbonate; cyclic ethers such as tetrahydrofuran (THF) and2-methyltetrahydrofuran; cyclic esters such as 1,3-dioxolane and4-methyldioxolane; lactones such as γ-butyrolactone; sulfolane;3-methylsulfolane; dimethoxyethane, diethoxyethane, ethoxymethoxymethaneand ethyldiglyme. These solvents may be used alone or in combination oftwo or more. The concentration of the electrolyte in the liquidelectrolyte should preferably be 0.3 to 5 mol/I. Usually, theelectrolyte shows the highest conductivity in the vicinity of 1 mol/l.The liquid electrolyte should preferably account for 30 to 70 percent byweight, and especially 40 to 60 percent by weight of the electrolyte.Aqueous electrolytes comprise acids or salts in water which enhance thefunctioning of the cell. Preferred salts and acids include sulfuricacid, sodium sulfate or potassium sulfate salts. The salt or acid ispresent in a sufficient amount to facilitate the operation of the cell.The concentration may be about 0.5 weight percent of greater based onthe weight of the electrolyte, about 1.0 or greater or about 1.5 weightpercent or greater. A preferred electrolyte in a lead acid battery issulfuric acid in water.

The articles may comprise a seal between the transverse channels and thepost. The seal may be located in the channel, about the exterior of thechannel or both. The seal may comprise any material or form thatprevents electrolyte and gasses evolved during operation from leakingfrom the electrochemical cells. The seal can be a membrane, sleeve orseries of matched inserts and/or bosses in the plates and/or separatorsor inserted in the channel. The membrane can be elastomeric. The channelcan be formed by a series of sleeves, bushings, inserts and/or bosses,inserted or integrated into the plates and/or separators. The insertsmay be compressible or capable of interlocking with one another to forma leak proof seal along the channel. The inserts may be formed in placein the battery plates and/or separators, such as by molding them inplace. The inserts may be molded in place by injection molding. The sealcan be prepared from any material that can withstand exposure to theelectrolyte, operating conditions of the electrochemical cells andforces exerted by inserting the post or by the post in the channel. Thepreferred polymeric materials that are described as useful for the postsand the substrates. The seal may be formed by sleeves, inserts orbushings placed between the bipolar and monopolar plates. The sleeves orinserts can relatively rigid and the bushings will generally beelastomeric. The inserts, bosses, sleeves and\or bushings may be adaptedto fit within indentations in the bipolar and monopolar plates and/orseparators or to have ends that insert into the holes of the platescreating the transverse channels. The dual polar, bipolar and monopolarplates can be formed or machined to contain matching indents for thebosses, inserts, sleeves and/or the bushings. Assembly of the stack ofplates with the bosses, inserts, sleeves or bushings may createinterference fits to effectively seal the channels. Alternatively thebosses, inserts, sleeves and/or bushings may be melt bonded oradhesively bonded to the plates so as from a seal at the junction.Alternatively the bosses, inserts, sleeves and/or bushings may be coatedin the inside with a coating which functions to seal the channel. Asmentioned above the posts can function to seal the channels. It iscontemplated that a combination of these sealing solutions may beutilized in single channel or in different channels. The components ofthe stack of plates, including dual polar, monopolar plates and bipolarplates, preferably have the same shape and common edges. Thisfacilitates sealing of the edges. Where separators are present theygenerally have a similar structure as the battery plates to accommodatethe formation or creation of the transverse channels. In anotherembodiment the seal may be a thermoset polymer, such as an epoxy,polyurethane or acrylic polymer injected between the bolt and thetransverse channel. The sealing surface of the plate may be modified toimprove sealing when compression is applied by the posts. The sealingsurface may be smoothed, contoured, roughened or surface treated. Asmooth surface will have large contact area from which to make anelectrolyte tight seal without defects that allow liquid flow. Contourssuch as concentric ring(s), ridge(s) or undulations cause areas or“rings” of high pressure contact to resist the flow of liquidelectrolyte. The ridge may be filled with a gasket material such as adeformable flat sheet or o-ring to facilitate liquid sealing. Roughsealing surfaces of a deformable material can compress to form reliableliquid electrolyte seal. Surface treating the sealing surface to make itincompatible to wetting by the liquid electrolyte will prevent liquidelectrolyte flow into the channel. If a hydrophilic electrolyte is usedthe sealing surface can be made hydrophobic. Likewise, if a hydrophobicelectrolyte is used the sealing surface should be hydrophilic. Thechannels may be formed by bosses, sleeves or bushings bonded to or inholes in the battery plates and inserts integral to the holes in theseparators, for example absorbent glass mats, wherein the holes in thebattery plates, inserts integrated in the holes of the separators andthe bosses, sleeves or bushings are aligned to form the channels. Theposts in a plurality of the channels may apply sufficient pressure tohold the inserts, holes, bosses, sleeves and/or bushings in place toform a sealed passage. The channels may be formed from bosses bonded tothe battery plates and inserts integrated into the separators. The postsmay be bonded to the inserts, bosses and/or substrates of the battery byan adhesive bond or by fusion of thermoplastic polymers or both. Theinserts may be inserted in battery plates or separators by interferencefit or bonded in place by an adhesive. Inserts in the separators maycontain vent holes that allow communication between the electrochemicalcells and the channels formed. The vent holes may allow transmission ofgasses from the electrochemical cells to the channel and prevent thetransmission of liquids from the electrochemical cells to the channels.

The edges of the battery plates and the separator plates are sealed toprevent leakage of the electrolyte and evolved gasses from the cells andisolate the individual cells to prevent short circuiting of the cells.The edges can be sealed using any known battery sealing method. Theedges of the assembly may be sealed using the endo or exoskeletonsealing systems disclosed in commonly owned patent application, Shaffer,II et al. Bipolar Battery Assembly, US 23010/0183920 Al incorporated itsentirety herein by reference. The sealing system disclosed in Shaffer,II et al. contemplates unique structures for a bipolar battery laminatestructure, such as structures described above. The structures, whetherfrom the above methods or not, generally comprise a first separatorframe; a negative pasting frame member having one or more edges and asupporting grid structure extending between the one or more negativepasting frame edges; a negative current collector foil; a substratehaving a plurality of openings formed therein; a positive currentcollector foil; a positive pasting frame member having one or more edgesand a supporting grid structure extending between the one or morepositive pasting frame edges and a second separator frame. The firstseparator frame may include one or more edges. The negative pastingframe member may have one or more edges so that at least one edge of thenegative pasting frame member is in planar contact with at least oneedge of the separator frame. The substrate may also have one or moreedges so that at least one edge of the substrate is in planar contactwith at least one edge of the negative pasting frame member. Thepositive pasting frame member may have one or more edges so that atleast one edge of the positive pasting frame member is in planar contactwith at least one edge of the substrate. The second separator frame mayhave one or more edges so that at least one edge of the separator frameis in planar contact with at least one edge of the positive pastingframe member. The planar contact of the edges of the separator frames,the negative and positive pasting frame members and the substrate forman external seal on the battery so that an electrolyte introducedtherein will not leak from within the battery. The edges of the pastingframe members may further include openings for receiving alignment pinsor support members located on the edges of the separator frames. Thelocating of the alignment pins into the openings on the pasting framemembers may further facilitate the forming of the external seal. It alsois envisioned that a frame structure may be used by which one or moreseparator frames and one or more pasting frames, in combination with thesubstrate, will each lie in planar contact with adjacent frames and/orsubstrates so that the internal structure of the battery cell creates anexternal seal that prevents any liquid or gas (air) from escaping thebattery. The edges of the pasting frame members may further includeopenings for receiving alignment pins or support members located on theedges of the separator frames. The locating of the alignment pins intothe openings on the pasting frame members may further facilitate theforming of the external seal. Thus, any electrolyte introduced into thebattery will be securely maintained without risk of battery leakage andsubsequent battery failure. Further, no heavy end plates or externalsupport structures are required to effectively seal the battery. Asmentioned above, the pasting frame members may further include supportmembers (e.g., pins) located between the edges of the pasting framemembers. The use of support members is just one approach to address theissue of compressive stress and resulting unwanted edge/peeling stresswithin the battery. These stresses may lead to undesirable batteryleakage as discussed above. This use of the support pins within abattery, and the resulting internal approach discussed herein, maytherefore be referred to as building a bipolar battery having anendo-skeleton. A feature of using the endo-skeleton build orconstruction approach (as compared to using an exo-skeleton buildapproach) to address the undesired effects of compressive stress withinthe battery, is that it does not result in a reduction of volumetricenergy density. Additionally, it is a lightweight approach, using only afew lightweight pins with very little loss of active material. Further,the endo-skeleton build approach has been found to greatly reduce thechances of traditional bipolar battery failure mode caused by edgepeeling. Further, if desired, one can add pins on the perimeter or edgeof the frame members to align the separating frame member, therebyallowing it to glide up and down or back and forth during compression.If desired, the bipolar battery may be constructed using a combinationof an endo-skeleton and exo-skeleton build approach. For example, thebipolar battery can be constructed using internal support pins asdescribed above. In addition to this, a frame structure may also beplaced on the terminal side of the monopole. This exterior batteryconstruction may be reinforced with an end cover as part of an aestheticbox. The combined features of an endo-skeleton and an exo-skeleton insuch a construction work together to further reduce maximum edge stressand displacement. The bipolar battery may also be substantially free ofany exo-skeleton structure. In one embodiment the substrates for thebattery plates can have a raised edge about the periphery of thesubstrates which function as pasting frames for the cavity containingthe electrolyte, and optional separator, to seal against one another andto seal to an outside membrane when utilized.

The edges of the stack of monopolar and bipolar plates may have adheredto a membrane. The membrane may be bonded to the edge of the plates byany means that seals the edges of the plate and isolate theelectrochemical cells. Exemplary bonding methods comprise adhesivebonding, melt bonding, vibration welding, RF welding, and microwavewelding among others. The membrane is a sheet of a polymeric materialwhich material can seal the edges of the monopolar and bipolar platesand can withstand exposure to the electrolyte and the conditions thebattery is exposed to internally and externally. The same materialsuseful for the substrate of the bipolar plates may be utilized for themembrane. The membrane may be a thermoplastic polymer that can be meltbonded, vibration welded or molded about the substrates of the monopolarand bipolar plates. The same thermoplastic polymer may be utilized forthe monopolar and bipolar substrates and the membranes. Exemplarymaterials are polyethylene, polypropylene, ABS and, polyester, with ABSmost preferred. The membranes may be the size of the side of the stacksto which they are bonded and the membranes are bonded to each side ofthe stack. The edges of the adjacent membranes may be sealed. The edgescan be sealed using adhesives, melt bonding or a molding process. Themembranes may comprise a single unitary sheet which is wrapped about theentire periphery of the stack. The leading edge of the membrane, firstedge contacted with the stack, and the trailing edge of the stack, endof the membrane sheet applied, are may be bonded to one another tocomplete the seal. This may be performed by use of an adhesive, by meltbonding or a molding process. In melt bonding the surface of themembrane and/or the edge of the stack are exposed to conditions at whichthe surface of one or both becomes molten and then the membrane and theedge of the stack are contacted while the surfaces are molten. Themembrane and edge of the stack bond as the surface freezes forming abond capable of sealing the components together. The membrane may betaken from a continuous sheet of the membrane material and cut to thedesired length. The width of the membrane may match the height of thestacks of monopolar and bipolar plates. The membrane has sufficientthickness to seal the edges of the stack of monopolar and bipolar sheetsto isolate the cells. The membrane may also function as a protectivecase surrounding the edges of the stack. The membrane may have athickness of about 1 mm or greater, about 1.6 mm or greater or about 2mm or greater. The membrane may have a thickness of about 5 mm or less,4 mm or less or about 2.5 mm or less. When the membrane is bonded to theedge of the stack, any adhesive which can withstand exposure to theelectrolyte and the conditions of operation of the cell may be used.Exemplary adhesives are plastic cements, epoxies, cyanoacrylate glues oracrylate resins. Alternatively, the membrane may be formed by molding athermoplastic or thermoset material about a portion of, or all of, thestack of battery plates. Any known molding method may be used includingthermoforming, reaction injection molding, injection molding, rotomolding, blow molding, compression molding and the like. The membranemay be formed by injection molding the membrane about a portion of orall of the stack of battery plates. Where the membrane is formed about aportion of the stack of the plates it may be formed about the edges ofthe battery plates or battery plates and the separator.

The sealed stack may be placed in a case to protect the formed battery.Alternatively the membrane in conjunction with a protective coveringover the monopolar plates at the end of the stack may be used as a casefor the battery. The monopolar plates may have an appropriate protectivecover attached or bonded to the surface opposite the anode or cathode.The cover may be the same material as the membrane or a material thatcan be adhesively bonded or melt bonded to the membrane and can have athickness within the range recited for the membranes. If affixed to theend of the plates the cover can be affixed with any mechanicalattachment including the posts having overlapping portions. The case maybe formed by molding a membrane about the stacks of battery platesand/or the opposite sides of the monopolar plates.

The assemblies may further comprise one or more conductive conduitsadapted to transmit electrons from the current collectors in contactwith the cathodes to one or more positive terminals. A typical bipolarbattery flows electrons from cell to cell through the substrate. Eitherthe substrate at least partially comprises a conductive material orcomprises conductive pathways through the substrate. When the circuit isclosed that contains the cells electrons flow from cell to cell throughthe substrate to the positive terminal. It is contemplated that theassemblies may flow electrons through the substrates and cell, through acurrent collector to a current conductor or both. The assembliesdisclosed further have conductive conduits which contact the currentcollectors or current conductors in contact with the anodes to thenegative terminals. In the batteries disclosed herein having two or morestacks, each stack has a current conductor and/or a conductive conduitcontacting the current collectors in contact with the anodes with anegative terminal and a current conductor and/or a conductive conduitcontacting the current collectors in contact with the cathodes with apositive terminal. The conductive conduits from the two or more stacksmay be arranged in parallel or in series. Parallel circuits comprise twoor more circuits that are not connected to one another. Series circuitscomprise two or more circuits that are arranged such that electrons flowthrough the circuits sequentially. When the conductive conduits arearranged in a series configuration the battery may have only onenegative terminal and one positive terminal. When the conductiveconduits are arranged in a parallel manner the battery may have singlepositive and negative terminals in which each circuit connects with eachof the negative or positive terminals. Alternatively each circuit mayhave separate negative and positive terminals. The terminals may beconnected to the load which typically utilizes the electricity stored inthe battery. Each of the current conductors and/or current conduits incontact with current collectors in contact with cathodes in a parallelarrangement may be contacted with separate positive terminals. Each ofthe current conductors and/or current conduits in contact with currentcollectors in contact with anodes in a parallel arrangement may becontacted with separate negative terminals. The individual terminals maybe covered by a membrane leaving only a single connected positive andnegative terminal exposed wherein the covered negative terminals areconnected with the exposed negative terminal and the covered positiveterminals are connected with the exposed positive terminal.

The assembly may contain one or more pairs of conductive terminals, eachpair connected to a positive and negative terminal. The terminals areadapted to connect each battery stack to a load, in essence a systemthat utilizes the electricity generated in the cell. The terminals arein contact with the conductive conduits in the assemblies. The assemblymay contain pressure release valves for one or more of the cells torelease pressure if the cell reaches a dangerous internal pressure. Thepressure release valves are designed to prevent catastrophic failure ina manner which damages the system the battery is used with. Once apressure release valve is released the battery is no longer functional.The assemblies disclosed may contain a single check valve which releasespressure from the entire assembly when or before a dangerous pressure isreached.

The assemblies disclosed are attached to a load and a circuit is formedwhich includes the cells. Electrons are flowed to the terminals and tothe load, a system using the electricity. This flow is maintained aslong as the cells can generate electricity. If the stack of cellsbecomes fully discharged the battery needs to undergo a charging stepbefore additional use. If the substrate for the bipolar plates containsan electrically conductive material admixture at an operatingtemperature of the battery assembly that is below its phasetransformation temperature, the substrate has an electrically conductivepath via the material admixture, between a first surface and an opposingsecond surface of the substrate, and at a temperature that is above thephase transformation temperature of the conductive material admixture,the electrically conductive material admixture undergoes a phasetransformation that disables electrical conductivity via theelectrically conductive path. This allows the disabling of the batterybefore untoward consequences occur. Once a battery is discharged it maybe recharged by forming a circuit with a source of electrons. Duringcharging the electrodes change function and the anodes during dischargebecome cathodes and the cathodes during discharge become anodes. Inessence the electrochemical cells flow electrons and ions in oppositedirections as compared to discharge.

The assembly disclosed may be prepared by the following steps. Thesubstrates for the bipolar plates, dual polar plates and monopolarplates are formed or cut to shape. If the substrate comprises anonconductive material and a traditional bipolar battery is beingassembled, the substrate needs to be converted to a composite substrate.Means of achieving this is by forming holes through the substrate by anyknown means, such as molding them in or machining the substrate to fromthe holes. The openings are filled with conductive material, preferablyconductive material that melts at a defined temperature as describedhereinbefore. If utilized the metal sheets, screens, wires or foil areadhered to one or both of the faces of the substrate. Preferably themetal sheets or foil are bonded to the substrate using an adhesive asdescribed hereinbefore, preferably a nitrile based rubber cement. Thecathode and anode are attached to the substrate or the metal sheets,screens, wires or foil. The attachment is facilitated using any standardcathode or anode attachment method. Where the cathode and anode are usedin a paste form, the paste is applied to the substrate or to the metalsheet, screen, wire or foil. The paste is allowed to dry. The holes forthe transverse channels may be pre-formed or machined into thesubstrate, metal sheets or foil, separator, anode, cathode and any othercomponent present. Where the channels are formed using sleeves, insertsor bosses and the like, they are inserted into the battery plates and/orthe separators. Where the inserts are molded in place they are molded inplace using known molding processes. The components are then stackedsuch that for each plate an anode faces a cathode of another plate.Preferably the sheets are stacked so that the edges of the substratesare aligned along with the edges of any other frame components. In oneembodiment a plate with two or more guide pins or bolts is used tosupport the stack. The components are stacked on the plate with theguide pins in an appropriate order consistent with the disclosureherein. Two or more of the transverse channels may be used for thealignment pins or bolts. Once the stack is completed, elastomericmembranes or sleeves may be inserted into the transverse channels. Ifthe channel is sealed with bushings, inserts or plastic sleeves locatedbetween the holes in the plates a coating may be applied to the interiorof the channel, interior of the holes, sleeves inserts and/or bushings.If the interior of the holes of the plates need to be threaded they arethreaded either prior to assembly or after assembly using knowntechniques. Thereafter posts are inserted into the stack and secured bythe overlapping portion to the sealing surface of the opposing side ofthe monopolar plates. Where the overlapping portion is a mechanicalattachment structure, such attachment structure is secured to the post.Where the post is injection molded in place, molten thermoplasticmaterial is inserted into the channels and an overlapping portion of themolten material is formed on the sealing surfaces at both ends. Thesurface of the channels may be heated to melt the surface of the insideof the channels, in this embodiment the injected thermoplastic materialbonds well to the inside of the channel. The thermoplastic material isallowed to cool. In another embodiment the channel may have a forminserted into the channels and a form for the overlapping portion of theformed at each end. A two-part thermoset material is then added to thechannels and allowed to cure to form the post. Where the post isdesigned to fit into the channel by interference fit the post isinserted with appropriate force. Once the posts are secured and stable,the stack is removed from the guide pins and posts can be inserted intothe channels used for the guide pins.

Where a membrane is applied to the edge surface of the stack, anadhesive is applied to either or both of the membrane or the edge of thestack and the membrane and the edge of the stack are contacted so as tobond them together. The membrane may be held in place while the adhesivesets or cures using known mechanical means. The edges of the membranecan be sealed to the unsealed edges of other membrane sheets ormembranes or end plates on the opposite surface of the monopolar plates.The sealing can be performed by an adhesive or by melt bonding.Alternatively the membrane can be attached by melt bonding. In meltbonding both the edge of the stack and the surface of the membrane to bebonded to the edge are exposed to conditions such that the surface meltswithout negatively impacting the structural integrity of the membrane orthe stack. This can be achieved by contacting each with a hot surface,platen, hot fluid, air, radiation, vibration and the like, thencontacting the membrane and edge of the stack along the melted surfaceand allowing the molten surfaces to cool and bond together. The membranemay be cut to fit a particular edge or can be a continuous sheet whichis wrapped around the edge of the stack. In this embodiment the leadingedge and the trailing edge of the membrane are bonded together wherethey meet, preferably by melt bonding. The membrane may be sealed to themembrane or endplate on the outside surface of the monopolar plates,where present. Where a case is used the assembly may be inserted intocase. Preferably the membrane functions as a case. In the melt bondingembodiment, the membrane and edge of the stack are exposed to atemperature or condition at which the surface of each is melted, becomesmolten, for a time sufficient to melt the surface of each. Thetemperature chosen is preferably above the melting temperature of thematerial used in the membrane and/or the substrate and any otherstructural components. Preferably the temperature used is about 200° C.or greater, more preferably about 220° C. or greater and most preferablyabout 230° C. or greater. Preferably the temperature used is about 300°C. or less, more preferably about 270° C. or less and most preferablyabout 240° C. or less.

The frames and/or inserts may be molded into or onto the separators orthe battery plate substrates using the following steps. The separatorsheets are cut to size (die punch, slit, stamped, etc). One or moresheets are stacked to meet the required thickness. The sheets are placedinto a mold that places the sheets into a fixed position. The mold formsthe periphery frame around the separator and any internal features aboutthe transverse channels (e.g. bushings) as required. Further the mold isdesigned to not overly compress the separator material and to preventplastic from damaging the separator material. Plastic is the injectedinto the mold and once the plastic is cooled the part is ejected.

The membrane may be molded about a portion of or all of the batterystacks utilizing the following steps. Components of the battery arestacked in appropriate order (end plate, monopolar plate, separator,bipolar plate, etc). The stack alignment can be assured by using theguide rods through the transverse holes of each stacked component. Thestacked assembly is then transferred into the mold which consists of apositive mold cavity, a negative mold cavity, an insert mold cavity forthe body of the battery (alternatively slide doors could be used as iscommon in injection molding) and retractable guide pins located ineither the negative mold cavity or the positive mold cavity. The stackedassembly is transferred onto the retractable guide pins to ensure andmaintain alignment. The mold is then closed which compresses theassembly. Plastic is then injected to form the outer membrane of thebattery sealing to the components and end plates. The guide pins arethen retracted and a second shot of plastic is injected filling thetransverse channels and securing the injected plastic to the end plates.Once cooled the battery is ejected from the mold.

The assembly may further comprise one or more vent holes leading intoone or more of the electrochemical cells. The vent holes allow gasses tovent from the electrochemical cells and electrolyte liquids to beintroduced to electrochemical cells with either pressure applied to movethe liquid into the cells or a vacuum pulled on the electrochemicalcells to pull the electrolyte through the vent holes into the cells. Inthe embodiments where electrolyte is introduced using a vacuum, eachcell may have two vent holes wherein a vacuum is applied to one venthole so as to pull electrolyte into the cells from the other vent hole.The vent holes may be in contact with any combination of manifolds andchannels. A vent hole may be in contact with each electrochemical cell.The vent holes may be in contact with the battery separators for eachcell. The assembly may comprise a manifold. The one or more vent holesmay be in contact with the manifold and the manifold may form a commonhead space for all of the vent holes. The manifold has one or more portsformed therein where one or more valves, such as a check valve, may beplaced in the manifold ports. The battery may further comprise a fillvalve. The fill valve may be located in the manifold or connected to atransverse channel. The article may further comprise one or moreintegrated filling and/or venting channels. Such a channel is formednear the center of a battery stack and is in communication with the areabetween the cathode and anode where the separator is located, this isthe area that forms the electrochemical cell when electrolyte is addedto the area. The channels can be formed by forming holes or slots in theseparators and battery plates before assembly and then aligning theholes or slots. Inserts, sleeves or bosses may be used as discussedherein with respect to the transverse channels as long as the channelscommunicate with the area adapted for use as electrochemical cells.Preferably the channels communicate with the outside of the batterystack in two places. This facilitates filling of the battery withelectrolyte. After filling of the electrochemical cells with electrolyteone of the openings can be filled or closed. The other opening is usedto vent the battery and the electrochemical cells. During filling avacuum is pulled on one external hole and electrolyte is drawn inthrough the other hole. Alternatively a single hole is used and theelectrochemical cells are filled as described herein after. In thisembodiment once the sealed battery is formed, a vacuum is pulled on thesingle hole or port to create a low pressure environment in the cells.The pressure in the electrochemical cells may be 50 Torr or less or maybe 10 Torr or less. The vacuum is then disconnected and a source ofelectrolyte is connected to the hole or port and the electrolyte quicklyfills the battery due to the low pressure in the cells. The vacuumapparatus and the source of electrolyte may be connected through aswitchable valve so that switching from vacuum to the source ofelectrolyte can be performed in an efficient manner. This system may beutilized where one transverse channel is formed from sleeves, insertsand/or bosses having vent holes, such as notches in the bosses, insertsor sleeves, in contact with the electrochemical cells. This systemallows for even filling of the electrochemical cells with freshelectrolyte. Filling under these conditions can take place in about 600second or less or about 300 second or less. A valve, such as a checkvalve, pop valve, pressure relief valve and the like, may be insertedinto the remaining hole after filling. The channel can be pre-threadedor tapped after assembly of the stack.

After assembly, vent holes may be drilled if necessary through thesealed membrane into each cell centrally located on the thickness of theabsorbent glass mat separator. A manifold is then attached to the top ofthe battery assembly forming a common head space above the vent holes.In the manifold a single port may be fabricated. The single manifoldport may be used as a vacuum purge port and an electrolyte fill port.Vacuum is applied to the manifold port via vacuum pump to low pressures,such as about 29 inches Hg, then the vacuum source valve is turned off,the fill valve is connected to a source of electrolyte is openedallowing electrolyte to fill all cells of the battery simultaneously.The vent holes may be formed in the frames about the separator when theframes are fabricated or molded. An integrated vent channel may beformed by predrilling or forming holes in the frames of the separatorsand the substrates used for the battery plates. These holes can bealigned to form a channel. This channel may communicate with the ventholes that communicate with the electrochemical cells. The integratedvent channel may be one of the transverse channels wherein thetransverse channels have a vent hole communicating with each of theelectrochemical cells. There may be two integrated channels with ventholes communicating with each electrochemical cell. Formation of anintegrated channel can be achieved by providing a membrane or insert inthe transverse channel with vent holes for each electrical chemicalcell. The channel may be formed from inserts, sleeves or bosses whichhave vent holes or form vent holes which communicate with theelectrochemical cells. The integrated channels may be pressurized toprevent backflow of electrolyte. The integrated channel may beterminated with a valve to control the internal pressure of theassembly. Before use the channel may be used to fill the electrochemicalcells with electrolyte. The valve may be located on one of the endplates. The channel can be threaded after assembly or can bepre-threaded prior to assembly for insertion of a valve. The valve maybe inserted and retained using any known means for insertion andretention. Some of the components used in the articles disclosed hereinare adapted to be disposed adjacent to other components disclosed.Components that are designed to be located to other components may haveor utilize components or techniques known in the art for retaining theparts in the appropriate relationship to one another. The particularcomponents or techniques used to retain components in relationship toone another are selected based on the components, relationship anddesign preferences of the skilled artisan designing or assembling theassemblies of the invention.

The assemblies can withstand internal pressures of 10 psi or greaterwithout leaking or warping due to the internal pressures, about 20 psior greater, about 50 psi or greater and about 100 psi or less. Theassemblies can withstand internal pressures of about 6 to about 10 psi.The assemblies may provide an energy density of about 34 watt hours perkilogram, about 40 watt hours per kilogram or about 50 watt hours perkilogram. The assemblies of the invention can generate any voltagedesired, such as 6, 12, 24, 48 or 96 volts. The voltage can be higheralthough about 200 volts is a practical upper limit.

The following figures illustrate some embodiments of the invention. FIG.1 shows a side view of a stack of bipolar plates 10. Shown are a numberof monopolar and bipolar plate substrates 11. Adjacent to each bipolarplate substrate 11 are anodes 12 and cathodes 13. Disposed between theanodes 12 and the cathodes 13 of each cell is a separator 14 comprisingan absorbent glass mat having electrolyte absorbed therein. Also shownis a channel seal 15 comprising a rubber tube disposed in a transversechannel 16. In the transverse channel 16 inside the rubber tube of thechannel seal 15 is a post 17 in the form of a threaded bolt. At the endof the posts 17 are overlapping portions in the form of bolt heads 18and nuts 19. About the edge of the substrates of the monopolar 43 andbipolar plates 44 are frames 20. FIG. 2 shows an end plate 25 disposedover the end of the opposite surface of the substrate 11 of a monopolarplate 43. A seal 22 is placed between the nut 19 on the post 17 and thesealing surface 23 on the monopolar plate opposing surface 24.

FIG. 3 shows applying a membrane about the edge of a stack of bipolarsubstrates. An end plate 25 is shown with four bolt heads 19 spacedapart on the end of bolts 17. End plates 25 are shown on each end of thestack. Disposed about the substrates 11 are frames 20. Between theframes of the substrates 20 are the frames for the separators 34. Amembrane 27 is being applied to the substrate frames 20 and theseparator frames 34 using a source of heat 26 and pressure 28 to sealthe membrane 27 to the edge of the stack of substrates frames 20 andseparator frames 34. FIG. 4 shows a bipolar battery 29 comprisingbattery plate stack 10 having substrate frames 20 interspersed withseparator frames 34. Shown are end plates 25, one showing four nuts 19spaced apart. Also shown are vent holes 30 drilled into the cells, amanifold 31 adapted to cover the vent holes 30 and form a common headspace for the vent holes 30. Also shown is a check valve 32 disposed onthe manifold 31 in contact with the common head space, not shown. Alsoshown are two terminal posts 33 which are the negative and the positiveterminals for the bipolar battery 29.

FIG. 5 shows a separator 14, a molded integrated frame 34 and fourmolded in inserts 35. The molded inserts 35 are located about moldedinsert holes 37 adapted to form part of the transverse channel 16. Theframe 34 is disposed about an absorbent glass mat 36. FIG. 6 showsmolded posts 38 and molded heads 47 located on the end plate 25. FIGS. 7and 8 illustrates stacks of battery plates and separator plates. FIG. 7shows a partially exploded stack of battery plates and separators. Shownis an end plate 25 having a terminal hole 42 and holes 39 for posts 17in the form of bolts and nuts 19. Adjacent to the end piece is amonopolar plate 43 having a frame 20 with a raised edge. The monopolarplate 43 has raised inserts 41 that surround holes used to form thetransverse channel 16 and post 17 in the holes. Adjacent to themonopolar plate 43 is a separator 14 having a frame 34 about theperiphery and an adsorbent glass mat 36 comprising the central portion.Molded inserts 35 surrounding molded insert holes 37 for forming thetransverse channels are shown. Adjacent to the separator 14 is a bipolarplate 44 having a frame 20 about the periphery which has a raisedsurface, raised inserts 41 which are raised to form the transversechannel 16. The raised inserts 41 form raised insert holes 40 for thetransverse channel. FIG. 8 shows the stack of battery plates andseparators. Shown are end plates 25, battery plate substrate frames 20,separator frames 34, posts 17, nuts 19 about the posts 17. A terminalhole 42 in the endplate 25 has a battery terminal 33 located therein.

FIG. 9 shows another embodiment of an assembly of the invention. Shownare posts 17 and nuts 19 on the endplate 25, a terminal hole 42 with aterminal 33 located therein, a manifold 31 and a check valve 32,Disposed about the periphery of the battery is a membrane 27. FIG. 10shows a cutaway along the plane shown by line A-A through the transversechannels. Shown is a monopolar plate 43 having a substrate 11 and acathode 13 having a frame 20 at the ends of the substrate 11. Adjacentto the cathode 13 on the monopolar plate 43 is a separator 14 having aframe 34 on each end. Adjacent to the separator 14 is a bipolar plate 44having an anode 12. The anode 12 is disposed on a substrate 11 and onthe opposite surface of the substrate 11 is a cathode 13 and disposed atthe end in this view is the frame 20. In this view there are number ofbipolar plates 44 arranged as described. Between the bipolar plates 44are separators 14. At the opposite end of the stack is a monopolar plate43 having a substrate 11, with a frame 20 shown at the ends in this viewand an anode 12 facing the adjacent separator 14. The pairs of batteryplates form electrochemical cells with the separators 14 located in thecells. Also shown are the transverse channels 16 having channel seals 15and posts 17 disposed therein and nuts 19 at the end of the posts 17.FIG. 11 shows a partial cut away view of the end of a stack of theassembly of FIG. 9 showing the vent holes along line B-B. FIG. 12 showsa cutaway view of the assembly of FIG. 9 though the vent holes 30 to theelectrochemical cells along plane C-C. Shown are vent holes 30 for eachelectrochemical cell.

FIG. 13 shows another embodiment of an assembly of the invention with avalve 50 in the end plate 25 of the assembly. The valve 50 communicateswith an integrated channel 46. The integrated channel 46 communicateswith the vent holes. FIG. 14 shows a cutaway view of the assembly ofFIG. 13 with an integrated channel 46 in communication with the ventholes 45 to the electrochemical cells along plane E-E. The integratedchannel 46 communicates with a valve 50 at the end of the stack. FIG. 15shows a cutaway view of the assembly of FIG. 13 though an integratedchannel 46 in communication with the vent holes 30 to theelectrochemical cells along plane D-D.

FIG. 16 illustrates a separator 14 having an absorbent glass mat 36 asshown in FIGS. 5 and 7 containing a vent (vent hole) 51 in one of themolded in inserts 35 having a hole 37. The vent 51 communicates withbetween the hole 37 and the absorbent glass mat 36 of the separator.Also shown is the frame 34 about the separator 14. A cut out portion ofFIG. 16 shows a close up of the insert 35 having a hole 37 and the vent51 wherein the vent 51 communicates between the hole 37 and theabsorbent glass mat 36 of the separator 14. FIG. 17 shows a side view ofa cut out from a separator 14 having an insert 35 with a vent 51communicating between the hole 37 and the absorbent glass mat 36. FIG.18 shows a portion of two bipolar plates 10 with a portion of aseparator 14 disposed between them. The inserts 47 in the bipolar platesand the separator 35 are aligned so that their holes 40 and 37respectively are aligned to form a portion of a vent/fill channel 46.Also shown are the substrate plates 11, anodes 12 and cathodes 13 of thebipolar plates.

FIG. 19 shows a dual polar battery plate 61, having an anode 12 and acathode 13 deposited on the conductive substrate plates 11. Shown is adual polar battery plate having a nonconductive substrate 57 thatprevents the flow of electrons across the plate. On each surface ofnonconductive substrate 57 is a conductive substrate 60 each of whichcontain a current collector 59 on the opposite face, wherein the currentcollectors 59 are disposed between the anode 12 and the cathode 13disposed on the conductive substrate 60. The positive current conductor56 is disposed between the nonconductive substrate 57 and the conductivesubstrate 60 connected to the cathode 13. The negative current conductor55 is disposed between the nonconductive substrate 57 and the conductivesubstrate 60 connected to the anode 12. Shown between the conductivesubstrates 60 and the anode 12 and the cathode 13 are current collectors59.

FIG. 20 shows a bipolar battery 62 having two stacks 10 of bipolarbattery plates 44, having an anode 12 and a cathode 13 deposited onconductive substrate plates 11. Shown is a dual polar battery plate 61as described in FIG. 19 disposed between the two stacks of batteryplates 10. The stacks of the battery plates 10 contain battery plates 44as described herein. The battery stacks 10 are arranged in parallel. Thenegative current conductors 55 are connected by a negative currentconduit 58. The outer most negative conductor 56, connected to theanodic monopolar plate 43 also functions as a negative terminal for thebattery. The positive current conductors 56 are connected by a positivecurrent conduit 62 the outer most positive conductor 56, connected tothe cathodic monopolar plate 43 also functions as a positive terminalfor the battery. The negative current conduit 58 connects the negativecurrent collector 55 to the negative terminal 54 of the battery. Thisfigure also shows monopolar plates 43 at each terminal end of the twostacks of battery plates and a membrane 27 disposed about the surface ofthe battery. The terminal negative current conductors 55 and positivecurrent collectors 56 pass through the membrane 27. Not shown in thisview is a transverse channel 16 having vent holes 30 in communicationwith the separators 14 located in the electrochemical cells which aredefined by the separators 14. The terminal negative current conductors55 and positive current collectors 56 pass through the membrane 27.

FIG. 21 shows a bipolar battery 62 having two stacks 10 of bipolarbattery plates 44 terminated on each end with monopolar battery plates43 having two dual polar battery plates 61 disposed between the stacksof bipolar plates 10. The stacks of bipolar plates 10 are arranged inseries. The negative current conductor 55 of each dual polar plate 61 isconnected by a current conduit 63 to the positive current conductor 56of the same dual polar battery plate 61. The outer most negativeconductor 55, which is in contact with the monopolar plate with ananode, also functions as a negative terminal for the battery. The outermost positive conductor 56, which is in contact with a monopolar platewith a cathode, also functions as a positive terminal for the battery.

Illustrative Embodiments

The following examples are provided to illustrate the invention, but arenot intended to limit the scope thereof. All parts and percentages areby weight unless otherwise indicated.

EXAMPLE 1

A 12V bipolar battery is built using two monopole plates (positive andnegative) and 5 bipolar plates. The plates are manufactured usingmethods as described herein and in commonly owned patent applicationtitled BIPOLAR BATTERY ASSEMBLY, Shaffer II, et al. U.S. Pat. No.8,357,469. The plates are pasted using standard lead-acid activematerials for the negative active material and positive active material.The battery is assembled using methods described herein and commonlyowned patent application titled BIPOLAR BATTERY ASSEMBLY, Shaffer II, etal. US2014/0349147. The battery uses standard absorbent glass matseparator material disposed between the positive and active material ineach cell as described in the commonly owned patent application titleBIPOLAR BATTERY ASSEMBLY US2014/0349147. The battery is filled with1.305 g/cc sulfuric acid using processes described in commonly ownedpatent application titled BIPOLAR BATTERY ASSEMBLY US2014/0349147. Thebattery is formed using common formation processes for lead acidbatteries. At the end of formation the battery is topped off with 1.363g/cc sulfuric acid resulting in a nominal open cell voltage of 13.25V.

EXAMPLE 2

A second battery is built using processes and materials identical toExample 1. In this example the battery is built using two monopolarplates (one positive and one negative) 10 bipolar plates and one dualpolar plate. The stack consists of one positive monopolar plate, fivebipolar plates, one dual polar plate, five bipolar plates and onenegative monopolar plate. Here the total amount of active material inthe battery is the same as in Example 1. The dual polar plate in thisexample is assembled by attaching a copper tab to the negative side of abipolar electrode, attaching a copper tab to positive side of a secondbipolar electrode, assembling the two bipolar electrodes with anon-conductive layer between the two bipolar electrodes and such thatthe copper tabs are on the side of the electrode attached to thenon-conductive plate. The tabs extend passed the bipolar electrode as tobe connected outside of the cell. Positive active material is pastedonto the positive conductive face of the first bipolar electrode in ofthe dual polar plate and negative active material is pasted onto thenegative conductive face of the dual polar plate. As a result the dualpolar plate has both positive and negative active material disposed oneither side similar to a standard bipolar plate but with the exceptionthat the active materials are electrically isolated from each other dueto the presence of the non-conductive plate. Further the extension ofthe copper tabs beyond the bipolar battery allow electricalcommunication to the two or more battery stacks. As in Example 1 theplates are pasted with identical active material recipes however withhalf the weight per plate as there are 2× the plates in this example. Asin example 1, absorbent glass mat material is placed between thepositive and active materials in each cell but similar to the paste ishalf the thickness. The stack is then assembled identical as Example 1.It is filled with acid 1.305 g/cc sulfuric acid to all cellsimultaneously using the same procedure as example 1. The formationprocess is the same and the battery is topped off at the end offormation with 1.363 g/cc acid. After formation the positive terminalattached to the positive monopole is connected with the positive tab ofthe dual polar plate and the negative terminal attached to the negativemonopole is connected with the negative tab of the dual polar plate. Asa result the two stacks are connected in parallel within a singlebattery case with a common valve port for both stacks.

The two batteries from example 1 and 2 are then measured and tested. Theresults are listed in Table 1. Both batteries have nearly identical sizewith example 2 being slightly heavier due to the additionalnon-conductive plate and tabs/terminals. As seen both batteries at the20 hour rate have similar capacities. However, the power is almost threetimes higher for the example 2 battery.

TABLE 1 Example 1 Example 2 Weight, g 4540 4950 OCV, V 13.23 13.21 20 hCapacity, Ah 16.92 16.21 Impedance, mOhm 46 15 Cold Cranking Amps, A 120360

Example 3 is modelled using conventional bipolar battery construction toachieve the specified performance of a Group 31 battery as specified bythe Battery Council International. Typical Group 31 batteries are listedin Table 2. To match the voltage capacity and cold cranking amps (CCA) aconventional bipolar battery construction would have large surface areaplates with thin active material and separator. This results in abattery well outside BCI specified size for a Group 31 limiting marketacceptance.

Example 4 is modelled using dual plate bipolar battery construction asdescribed in this patent application to achieve the specifiedperformance of a Group 31 battery as specified by the Battery CouncilInternational. The cell design of this battery (e.g. paste type,thickness, agm type thickness, acid type, etc) are the same as Example3. The results are listed in Table 2. As seen, using the disclosedstructures it is possible to build a bipolar battery that meets theGroup 31 battery specifications both in performance and size. This isnot achievable with a traditional bipolar mono-bloc.

TABLE 2 Dimensions, mm (Height × Voltage Capacity Depth × Weight DesignV Ah CCA A Length) kg Prismatic 12 100 700 240 × 173 × 330 31.5 VRLAConventional 12 100 800 460 × 58 × 460  23.2 Bipolar Bipolar 12 101 800240 × 138 × 330 23.5 using dual polar plate

Exemplary embodiments of the invention have been disclosed. A person ofordinary skill in the art recognizes that modifications fall within theteachings of this application. Any numerical values recited in the aboveapplication include all values from the lower value to the upper valuein increments of one unit provided that there is a separation of atleast 2 units between any lower value and any higher value. All possiblecombinations of numerical values between the lowest value and thehighest value enumerated are to be considered to be expressly stated inthis application. Unless otherwise stated, all ranges include bothendpoints and all numbers between the endpoints. The use of “about” or“approximately” in connection with a range applies to both ends of therange. Thus, “about 20 to 30” is intended to cover “about 20 to about30”, inclusive of at least the specified endpoints. The term “consistingessentially of” to describe a combination shall include the elements,ingredients, components or steps identified, and such other elementsingredients, components or steps that do not materially affect the basicand novel characteristics of the combination. The use of the terms“comprising” or “including” to describe combinations of elements,ingredients, components or steps herein also contemplates embodimentsthat consist essentially of the elements, ingredients, components orsteps. Plural elements, ingredients, components or steps can be providedby a single integrated element, ingredient, component or step.Alternatively, a single integrated element, ingredient, component orstep might be divided into separate plural elements, ingredients,components or steps. The disclosure of “a” or “one” to describe anelement, ingredient, component or step is not intended to forecloseadditional elements, ingredients, components or steps.

1. An article comprising: a) two or more stacks of battery platescomprising: (i) one or more bipolar plates comprising a substrate havingan anode on one surface and a cathode on an opposite surface, whereinthe substrates conducts current from the one surface to the oppsitesurface; (ii) a first monopolar plate disposed at one end of the two ormore stacks of battery plates, wherein the first monopolar platecomprises: 1) a cathode deposited on one surface; and 2) a currentcollector in contact with the cathode; (iii) a second monopolar platedisposed at an opposite end of the two or more stacks of battery platesas the first monopolar plate, wherein the second monopolar platecomprises: (1) an anode deposited on one surface, and (2) a currentcollector in contact with the anode; wherein the battery plates arearranged such that the surfaces of the battery plates having a cathodedeposited thereon face the surface of another battery plate having ananode deposited thereon; b) a liquid electrolyte disposed between eachpair of battery plates to form a plurality of electrochemical cells; c)a plurality of separator, wherein each individual separator is locatedbetween the anode and the cathode of an individual electrochemical cell;d) a dual polar battery plate disposed between two of the two or morestacks of battery plates, the dual polar battery plate comprising; (i) afirst conductive substrate having an anode material deposited on onesurface and a first current conductor in contact with a portion of anopposite surface; (ii) a second conductive substrate with a cathodematerial deposited on one surface and a second current conductor incontact with a portion of an opposite surface; and (iii) anon-conductive substrate disposed between the first conductive substrateand the second conductive substrate; wherein the dual polar batteryplate is arranged between two of the two or more stacks of batteryplates such that the surfaces of the dual polar battery plate having theanode material deposited thereon faces the surface of one of the batteryplates in a first battery stack having a cathode deposited thereon, andthe surface of the dual polar battery plate having a cathode materialdeposited thereon faces the surface of one of the battery plates in asecond battery stack having an anode deposited on the surface; and e)one or more conductive conduits which connects the first currentconductor and the second current conductor directly or indirectly tobattery terminals.
 2. The article according to claim 1, wherein thebipolar plates comprise polymeric substrates having a plurality ofopenings passing through the polymeric substrates in communication withboth surfaces of the polymeric substrates; and wherein one or more ofthe plurality of openings are straight, have smooth surfaces, and arefilled with a conductive material that undergoes a phase transformationat a temperature that is below a thermal degradation temperature of thepolymeric substrates.
 3. The article according to claim 1, wherein amembrane comprising a polymer is disposed about an entire periphery ofthe two or more stacks of battery plates, including about a periphery ofthe dual polar battery plate, so as to form a seal about edges of thebattery plates which prevents the liquid electrolyte from flowingoutside of the two or more stacks of battery plates.
 4. The articleaccording to claim 1, wherein one or more of the separators comprise asheet having an integrated frame adhered to a periphery of the sheet;and wherein the integrated frame is adapted to be placed adjacent to aperiphery of the substrates of the battery plates.
 5. The articleaccording to claim 4,, wherein the substrates of the battery plates haveraised edges about their periphery adapted to be disposed adjacent tothe integrated frames of the separator.
 6. The article according toclaim 1, wherein the article includes one or more openings in each ofthe separators, the one or more battery plates, the first monopolarplate, the second monopolar plate, and the dual polar battery plate; andwherein the one or more openings are aligned to form an integratedchannel; and wherein the integrated channel is transverse to a plane ofthe battery plates and the separators.
 7. The article according to claim6, wherein the one or more openings in the separators and the batteryplates contain inserts located therein; wherein the inserts are adaptedto mate to form the integrated channel between two or more stacks ofbattery plates and the integrated channel which passes through theliquid electrolyte; and wherein the inserts contain vent holes whichcommunicate between the integrated channel and the electrochemicalcells. 8-11. (canceled)
 12. The article according to claim 7, whereinthe inserts are bonded to or integral with the battery plates therebyforming seals at a junction between the separators and the batteryplates.
 13. (canceled)
 14. The article according to claim 1, wherein thetwo or more stacks of battery plates and the dual polar battery plateare connected in series by connecting the first current conductor andthe second current conductor for the dual polar battery plate throughone of the one or more conductive conduits.
 15. The article according toclaim 1, wherein current conductors connected to a cathode through aconductive substrate are connected through one or more conductiveconduits to a positive terminal, directly or indirectly and the currentconductors connected to an anode through a conductive substrate areconnected through one or more conductive conduits to a negativeterminal, directly or indirectly.
 16. The article according to claim 15,wherein internal sets of cells are independently electrochemicallyformed.
 17. The article according to claim 1, wherein the first currentconductor, the second current conductor, or both are placed in contactwith one or both of the monopolar plates.
 18. The article according toclaim 17, wherein the first current conductor and the second currentconductor are independently placed in contact with each of the monopolarplates.
 19. The article according to claim 18, wherein the first currentconductor and the second current conductor are terminal conductiveconnectors of the article and protrude through a case or membrane aboutthe article and function as the battery terminals or connect to thebattery terminals.
 20. The article of claim 17, wherein the individualterminals are covered in a membrane leaving only the single connectedpositive and negative terminal exposed.
 21. The article of claim 5,wherein the non-conductive substrate includes an integrated frame abouta periphery of the non-conductive substrate.
 22. The article of claim21, wherein the integrated frames of the separators and the integratedframes of the non-conductive substrate are adapted to match with theraised edges of adjacent battery plates to form a common edge and a sealbetween the electrochemical cells and an outside surface of the article.23. An article comprising: a) two or more stacks of battery platescomprising: (i) one or more bipolar plates comprising: 1) a substrate;2) an anode on one surface of the substrate; and 3) a cathode on anopposite surface of the substrate, wherein the substrate conductscurrent from the one surface to the opposite surface; (ii) a firstmonopolar plate disposed at one end of the two or more stacks of batteryplates, wherein the first monopolar plate comprises: 1) a cathodedeposited on one surface; and 2) a current collector in contact with thecathode; (iii) a second monopolar plate disposed at an opposite end ofthe two or more stacks of battery plates as the first monopolar plate,wherein the second monopolar plate comprises: 1) an anode deposited onone surface; and 2) a current collector in contact with the anode;wherein the battery plates are arranged such that the surfaces of thebattery plates having a cathode deposited thereon face the surface ofanother battery plate having an anode deposited thereon; b) a liquidelectrolyte disposed between each pair of battery plates to form aplurality of electrochemical cell; c) a plurality of separators, whereineach individual separator is located between the anode and the cathodeof an individual electrochemical cell, and wherein the separatorincludes a sheet having an integrated frame adhered about a periphery ofthe sheet; d) a dual polar battery plate disposed between two of the twoor more stacks of battery plates, the dual polar battery platecomprising: (i) a first conductive substrate having an anode materialdeposited on one surface and a first current conductor in contact with aportion of an opposite surface; (ii) a second conductive substrate witha cathode material deposited on one surface and a second currentconductor in contact with a portion of an opposite surface; and (iii) anon-conductive substrate disposed between the first conductive substrateand the second conductive substrate, wherein the non-conductivesubstrate includes an integrated frame about a periphery; wherein thedual polar battery plate is arranged between two of the two or morestacks of battery plates such that the surface of the dual polar batteryplate having the anode material deposited thereon faces the surface ofone of the battery plates in a first battery stack having a cathodedeposited thereon, and the surface of the dual polar battery platehaving a cathode material deposited thereon faces the surface of one ofthe battery plates in a second battery stack having an anode depositedon the surface; and e) one or more conductive conduits which connectsthe current conductors directly or indirectly to battery terminals; andwherein the integrated frames of the separators and the non-conductivesubstrate match with edges of adjacent battery plates to form a sealbetween the electrochemical cells and the outside of the article. 24.The article of claim 23, wherein the substrates of the battery plateshave raised surfaces about their periphery adapted to be disposedadjacent to the integrated frames and match to form a common edge. 25.The article of claim 24, wherein a membrane comprising a polymer isdisposed about an entire periphery of the two or more stacks of batteryplates, including about a periphery of the dual polar battery plate, soas to form a seal about edges of the battery plates which prevents theliquid electrolyte from flowing outside of the two or more stacks ofbattery plate.